Here is my entry into the Summer Puzzle-Building Competition.Groove CubeVIDEO!
The video explains it all. This puzzle is incredibly difficult, though not quite as difficult as Eric's (gingervergo's) Child's Play. I was able to do the first layer pretty easily, but the last layer is rather diabolical, as it's easy to lose track of where you are, since the whole thing is white. I ended up looking at my CAD drawing to solve the last layer this time, so that I could have the solved puzzle in the video. I'll try it again before Nationals, though.
I am currently working on trying to develop a good color scheme that doesn't change the difficulty at all (i.e. doesn't give anything away about the solution). <== Very hard to do... Any ideas would be welcome.
I'll post some more pictures in the competition page later today.